Pump jack



May 14, 1940. ECKERT 2200,7510

PUMP JACK Filed June 16, 1938 2 Sheets-Sheet l @2212," EEck'erZ IN VENTOR.

A TTORNEYS.

May 14, 1940. F. H. ECKERT rum? JACK Filed June 16, 1938 2 Sheets-Sheet.2

IN V EN TOR.

A TTORNEIYS.

Patented May 14, 1940 UNITED STATES PATENT OFFICE 5 Claims.

This invention relates to improvements in jacks for pumping wells andapplies particularly to pump jacks for use in pumping oil wells.

An object of the invention is to provide a jack that will require equalpower for its operation at all points during the up and down strokes.

Another object of the invention is to provide a jack which may beoperated either from compressed air or from natural gas which isavailable in some locations.

A further object of the invention is to provide parts without departingfrom the spirit of the invention as claimed.

In the accompanying drawings the preferred form of the invention hasbeen shown.

In said drawings,

Figure l is a side elevation of the jack in operating position.

Figure 2 is a'fragmentary view, partly in section, taken on the line2-2, Figure 1.

Figure 3 is a sectional view of the control and reversing valve taken onthe line 33, Figure 4.

Figure 4. is a sectional view of the valve taken on the line 44, Figure3.

Figure 5 is a sectional view of the valve taken on the line 5-5, Figure3 Figure 6 is an enlarged vertical section through one of the powercylinders.

Referring to the figures by characters of ref erence l designates asupporting frame the upper end of which is engaged by a pivot pin orbolt 2 which serves to connect the central portion of a Walking beam 3to the frame. Arcuate heads 4 are carried by the ends of the walkingbeam and one of these heads is connected by a line 5 to a sucker rod 6mounted for reciprocation within the stufilng box 1 at the upper end ofthe tubing 8. Another line 9 is secured to the other head 4 and extendsalong a guide column ID to a counterweight II which is slidable ,on thecolumn so as thus to be held against swinging. The weight of thecounter-balance can be varied by adding to or removing portions thereofso as to be equal to the weight of the rods in the well plus one-halfthe weight of the fluid being lifted.

Brackets or supporting members I2 are fixedly secured to the frame l andare formed in their top edges with notches or depressions l3 providingseats for pins I l. These pins are connected to the lower ends ofcylinders 15 and I6 respec- 5 tively in each of which is mounted the rodI! of a piston [8 which, as shown particularly in Figure 6, is providedwith a hydraulic cup I9 surrounding the piston and an expander ring 20.The upper end of each cylinder is closed by a cap 2| adapted 10 to besecured in placeby a set screw 22 or the like. Thus foreign matter canbe excluded from the upper end of the cylinder. As shown particularly inFigure 6 each pin is preferably joined to the lower end of its cylinderby welding and the lower 15 end plate or head of the cylinder, indicatedat 23 is provided with an inlet port 24. The upper end ofeach piston rodIT has an opening 25 for the reception of a pin 26 and each pin isadapted to be placed in any one of a series 20 of apertures 21 formed inplates 28 secured to the bottom of the Walking beam 3 at pointsequidistant from the pivots thereof. These openings 2'! correspond, intheir positions, to the depressions or notches I3 in the brackets I2thereunder so 5 that it is thus possible to bodily shift the cylindersalong the brackets to position their pins 14 in any of the depressionsand to correspondingly change the positions of the pins 26. By providingthis adjustment for the cylinders, they can be placed 30 in theiroutermost positions when the apparatus is working under a heavy load andlow air pressure whereas, when working under light loads and high airpressure, the cylinders can be moved in- Wardly toward each other,thereby decreasing the stroke of the piston and reducing airconsumption. A reverse valve has been indicated generally at 29 andextending from thisvalve are air lines 30, 3| and 32. An exhaust line 33is also extended from the valve. In the structure illustrated a tank 34is provided for holding compressed air used in operating the jackalthough it is to be understood that the jack can be operated fromnatural gas as hereinafter explained. This tank 34 can support a motor35 for driving a compressor 36 also mounted on the tank. Air compressedin the tank by compresso-r 36 is adapted to flow into the line. 30,there being a, valve 31 for controlling the flow of air from the tank tothe line.

Line 3| leads to the inlet 24 of cylinder l5 while line 32 leads to thecorresponding inlet of cylinder l6. Both of these lines have valves 38for the purpose of controlling the flow of air through the lines.

A shaft 39 is ,journalled in bearings 40 carried by frame I and thisshaft also extends through and is journalled within valve 29. Oppositelyextending crank arms 4! are secured to the respective ends of shaft 39by means of pins 42 or the like and each of these crank arms has a wristpin 43 loosely engaging in the lower link of a chain 44. Each chain isconnected to the walking beam 3 by means of a screw threaded adjustingrod 45, these rods being extended through arms 46 to which they are heldby nuts 41.

As the cranks 4| are extended in opposite directions, the mainconnections between them and the walking beam will cause a partialrotation of the valve parts on shaft 39 during the oscillation of thewalking beam.

The construction of thevalve mechanism has been clearly illustrated inFigures 3, 4 and 5. It will be noted that the body of the valve 29 iscomposed of three separate parts, 48, 49 and 5|), these parts beingsecured together by means of suitable bolts, or screws 50'. The highpressure line 30 is led into the part 48 and communicates with thepassage 5| leading to the ports 52 and 53 which are connected to theports 54 and 55, located in the part 49, by means of the drilledpassages 53, these passages being plugged attheir outer ends to preventescape of air. The. part 49 is also provided with the ports 51 and 58communicating with the lines 3| and 32 respectively, and the port 59communicating with the exhaust line 33. All of these ports and passagesare formed in the parts 48 and 49 and are stationary at all times.

Located inside the part' 48 and rotatably mounted on the shaft 39, is adisc valve 6|], held in position against the face of the member 49 bythe washer 6| and the spring 62 and provided with ports 53, 64 and 65.This valve is also provided with the hole. 55 to receive the actuatingPin 66.

The valve actuating mechanism, with the exception of the pin 66, islocated inside the part 50 of the valve housing. 'In describing theaction of the reversing mechanism the relative positions of the variousparts are shown in Fig. 5 by the full lines before reverse occurs and bythe dotted lines after reverse is completed. A member 5'! carrying stopfingers 68 and69, a coupling finger l0 and the pin 65 is rotatablymounted on the shaft 39. The fingers 68 and 69 are engageable withlatches H which are'held in contact with the fingers by the springs 12.The finger H! is positioned between the ends of a coil spring 53.Rigidly mounted on the shaft 39 and secured in position by pin 14, is amember l5 provided with a coupling finger l6 and two release fingers 11and 18.

As shown in Fig. 4, the arrows indicate the passage of air through thevalve, air from the high pressure line 3|! entering the passage 5|andpassing through the port '52 into the passage 56 and thenceconsecutively through the ports 54, '64 and 51 into the line 3| whichleads to the cylinder l5. It will be noticed that there is no flow ofair through the ports 55 or 65 when the valve is in this position, sincethe port 55 is the only opening leading into 65. The flow of air abovedescribed furnishes the power necessary to move the piston in thecylinder 15 during the up-stroke of the jack. Simultaneous with theadmission of air to thecylinder l5, the air in the cylinder It must bedischarged through the line 31, and into 'theexhaust line 33. It isshown that in this valve position, communication between the ports 58and 59 of the lines 33 and 34 respectively is' accomplished by the port63 in the valve 6|]. Thus, the air in cylinder I6 is free to exhaustWhile the power is being applied to cylinder l5.

When the walking beam reaches the upper limit of its stroke thedirection of air flow in the lines 3| and 32 must be reversed in orderthat power may be applied to the proper cylinder to make the downstroke. a partial rotation of the disc valve 69 (in a counter-clockwisedirection as viewed in 4) so as to connect the lines 36] and 32 by meansof the port 65, and, simultaneously establishing communication betweenthe lines 3|and 33 through the port 63. Thus, a reversal of the air fiowin the lines 3| and 32 is attained, thereby furnishing power for thedown stroke of the walking beam.

As the jack nears the upper limit of its stroke the lowermost link ofthe chain 44 will engage the wrist pin 43 of the crank 4| which isconnected to the shaft 39 by the pin 42 and further movement of the jackwill cause the shaft 39 to be rotated in a clockwise direction as viewed1 in Fig. 5. As the member 15 rotates with the shaft 39, the fingers H5,11 and 18 will rotate to the positions shown by dotted lines in Fig. 5causing the right hand end of the spring 13 to move with the finger 1B.the spring 73 is held in its original position by the finger 10 on themember 61 until near the last portion of the rotation. This is becausethe member 61 is not rigidly secured to the shaft 39 and is held againstrotation by the latch H which engages the finger 68 until the finger 11rotates far enough to disengage the latch H from the finger 58. Whenthis occurs, the left hand end of the spring 73 acting against thefinger 10 will cause the member 67 to rotate in a clockwise direction tothe position illustrated by the dotted lines, when the latch II willengage the finger 69 and hold it in this position. The rotary motion ofthe member 61 is transmitted through the pin 66 to the disc valve 5|].In this manner a. reversal of the air fiow throughv the lines 3| and 32is accomplished and the direction of the walking beam is reversed asbefore described.

The crank arm 4| limiting the down stroke is' placed on the oppositeside of'the shaft 39 so that when the walking beam reaches the limit ofits down stroke, the shaft 39 is caused to rotate in a counter-clockwisedirection as viewed in Fig.

The left hand end of This is accomplished by 5 and the reverseof theabove described actions takes place, returning the disc valve'fiil toits original position, as shown in Fig. 4.

It will be noticed that the arc formed by the head 4 has a radiuseq'ualto the distance from the head to the center of'the .pivot pin 2.construction imparts a straight line motion to the rod 6 and eliminatesstrain and Wear between the rod and the stuffing box The heads 4 are ofcourse rigidly attached to the beam 3.

This

As the rods H are connected to the beam 3 by 7 string of sucker rods-(which varies, of "course with the depth'of the wen) plus'the weight ofthe fluid being-lifted by the, pump. During the down stroke, no fluid isbeing lifted and, consequently,

the load on the well end of the walking beam is equal to the weight ofthe rods only.

Adjustment of the stroke length is accomplished by means of theadjusting rods 45 and the nuts 41, two independent adjusting rods beingemployed, the one on the well end governing the upper stroke limit andthe one on the rear end governingthe lower stroke limit. It is clearthat shortening the length of the adjusting member on the well end ofthe jack will result in decreasing the upper stroke limit, whileshortening the rear adjustment will decrease the down stroke limit.Conversely, lengthening the adjustment on either end will result in anincreased stroke limit for the corresponding stroke.

In using natural gas for power purposes, the mechanical operation of thejack is the same as above described except that the gas is piped to thereverse valve instead of using the compressed air. If necessary, aconventional pressure regulating valve may be incorporated in the gasline between the reverse valve and the source of sup-, ply. The exhaustline 33, for purposes of conservation, is led into a reservoir or flowline, the difference between the pressures on either side of the reversevalve being the net operating pressure.

The use of natural gas for power, in locations where it is available,greatly reduces the cost of pumping the well, both in the original costof the equipment and in maintenance.

The invention as above described comprises a simple, practical andeconomical means of producing oil from wells and while the preferredembodiment of the invention is here described it is to be understoodthat such changes as may be required to suit individual conditions maybe made so long as these changes do not depart from the spirit of theinvention.

What is claimed is:

1. In a pump jack, a walking beam, a valve housing, means for directingfluid under pressure to said housing, separate means operated by fluidunder pressure for oscillating the walking beam, said means beingconnected to the beam at opposite sides of its fulcrum, a rock shaftextending into the housing, means actuated by the Walking beam forimparting a back and forth rotation to said shaft, and a valve on theshaft and in the housing for directing the fluid under pressuresuccessively to the respective fluid-operating means and for exhaustingfluid from each of said means while pressure is being supplied to theother one of said means, said valve comprising cooperating fixed androtatable members, opposed latches, opposed stop fingers rotatable withthe movable valve member and into engagement with the respective latchesfor holding the valve member against rotation in either directionrespectively, a coupling finger movable with said stop fingers, releasefingers rotatable with the shaft against the respective latches todisengage them from the engaged stop fingers, a coupling finger movablewith the release fingers, and resilient means for transmitting thrustfrom one coupling finger to the other during their relative rotation.

2. In a pump jack, a walking beam, a valve housing, means for directingfluid under pressure to said housing, separate means operated by fluidunder pressure for oscillating the walking beam, said means beingconnected to the beam at opposite sides of its fulcrum, a rock shaftextending into the housing, means actuated by the Walking beam forimparting a back and forth rotation to said shaft, and a valve on theshaft and in the housing for directing the fluid under pressuresuccessively to the respective fluidoperating means and for exhaustingfluid from each of said means while pressure is being supplied to theother one of said means, said valve comprising cooperating fixed androtatable members, opposed latches, opposed stop fingers rotatable withthe movable valve member and into engagement with the respective latchesfor holding the valve member against rotation in either directionrespectively, a coupling finger movable with said stop fingers, releasefingers rotatable with the shaft against the respective latches todisengage them from the engaged stop fingers, a coupling finger movablewith the release fingers, and resilient means for transmitting thrustfrom one coupling finger to the other during their relative rotation,said resilient means including a spring loosely coiled about the axis ofrotation of the shaft and within the area defined by the paths ofmovements of the fingers, the terminals of the spring being spaced apartto straddle and yieldingly grip the coupling fingers.

3. The combination with a walking beam, a valve casing, a shaft in thecasing, a fixed valve member, a movable valve member cooperatingtherewith and means actuated by the walking beam for imparting a backand front rotation to the shaft, of means controlled by the shaft forimparting a delayed movement to the movable valve member during thecompletion of each movement of the shaft, said means including opposedlatches, opposed stop fingers movable successively into engagement withthe respective latches during'the completion of each movement of theshaft in one direction thereby to delay actuation of the fingers by theshaft when moved in the opposite direction, a coupling finger movablewith and interposed between said stop fingers, a connection between thesaid stop fingers and the movable valve member, spaced release fingersmovable with the shaft and positioned to engage and shift the respectivelatches during the completion of each movement of the shaft thereby torelease the retained stop finger, a coupling finger movable with therelease fingers and extended along but separate from the other couplingfinger, and yielding means engaging the coupling fingers fortransmitting thrust from one of said fingers to the other.

4. In a pump jack, a walking beam, a valve, means for directing fluidunder pressure to said valve, separate means operated by fluid underpressure for oscillating the walking beam, said means being connected tothe beam at opposite sides of its fulcrum, means actuated by the walkingbeam for imparting a back and forth rotation to said valve for directingthe field under pressure successively to the respective fluidoperatingmeans and for exhausing fluid from each of each means while pressure isbeing supplied to the other one of said means, said valve comprisingcooperating fixed and rotatable members, opposed latches, opposed stopfingers rotatable with the movable valve member and into engagement withthe respective latches for holding the valve member against rotation ineither direction respectively, a coupling finger movable with said stopfingers, release fingers rotatable with the shaft against the respectivelatches to disengage them from the engaged stop fingers, a couplingfinger movable with the release finfrom one coupling finger to the otherduring their relative rotation.

5. In a pump jack, a walking beam, a valve, means for directing fluidunder pressure to said valve, separate means operated by fiuid underpressure for oscillating the walking beam, said means being connected tothe beam at Opposite sides of its fulcrum, means actuated by the walkingbeam for imparting a back and forth rotation to said valve for directingthe fluid under pressure successively .to. the respectivefluid-operating means and for exhausting fluid from each of said meanswhile pressure is being supplied to the other one of said means, saidvalve comprising cooperating fixed and rotatable members, opposedlatches, opposed stop fingers rotatable with the movable valve memberand into engagement with the respective latches for holding the valvemember against rotation in either direction respectively, a couplingfinger movable with saidstop fingers, rel-ease fingers rotatable withthe shaft against the respective latches to disengage them from theengaged means including a spring loosely coiled about the axis ofrotation of the shaft and within the area defined by the paths ofmovements of the fingers,

the terminals of the spring being spaced apart to straddle andyieldingly grip the coupling fingers.

FELIX H. ECKERT;

